The demand for liquid crystal displays has been increased in applications such as liquid crystal TVs and liquid crystal displays of personal computers. In general, a liquid crystal display is constituted of a liquid crystal cell having a transparent electrode, a liquid crystal layer, a color filter, and the like, which are sandwiched with glass plates, and two polarizing plates provided in both sides of the liquid crystal cell, and each polarizing plate has a structure having a polarizer (also called a polarization membrane or a polarization film), which is sandwiched with two films (polarizing plate protecting films). For the above described polarizing plate protecting film, a cellulose ester film has been widely used because it has high transparency and can easily secure adhesiveness to a polyvinyl alcohol.
In addition, by arranging an optically biaxial retardation film between a polarizing plate and a liquid crystal layer of a liquid crystal display, it has been known that a wider viewing angel can be realized, that is, display characteristics can be improved. A cellulose ester film capable of expressing excellent optical performance has been focused also as such a retardation film, and a cellulose ester film is also used in a liquid crystal display as a retardation film.
However, since a cellulose ester film has high moisture permeability, the moisture permeates its inside to thus easily cause fluctuation in retardation values (phase difference values) of a retardation film and, as a result, there was a problem such as the occurrence of color unevenness of a liquid crystal display.
As a method of improving fluctuation in retardation values of the above described cellulose ester film, examples thereof include a method of making a film thickness small and a method of adding a large amount of an additive for controlling moisture permeability. However, when the film thickness is made small or when a large amount of an additive is added, a retardation value becomes small and a compound having high ability of increasing the retardation value is thus requested.
As a compound of having high ability of increasing a retardation value, examples such as 1,3,5-triazine-based compounds are suggested (for example, refer to Patent Literature 1).
In addition, in recent years, liquid crystal displays started to be used in televisions and large-sized monitors because of enhancement of its image quality and improvement of high-resolution techniques. In particular, demands such as increasing in sizes of these liquid crystal displays and cost reduction due to effective production are intensified also for materials of liquid crystal displays, and a retardation film is thus required to have a broad width.